package style.zcyLeetCode.a_0005_二叉树;

import java.util.LinkedList;
import java.util.Queue;

/**
 * 序列化与反序列化
 */
public class SerializeAndReconstructTree {
    public static class Node {
        public int value;
        public Node left;
        public Node right;

        public Node(int data) {
            this.value = data;
        }
    }

    // 序列化
    public static String serialByPre(Node head) {
        if (head == null) {
            return "#!";
        }
        String res = head.value + "!";
        res += serialByPre(head.left);
        res += serialByPre(head.right);
        return res;
    }

    // 反序列化
    public static Node reconByPreString(String preStr) {
        String[] values = preStr.split("!");
        Queue<String> queue = new LinkedList<String>();
        for (int i = 0; i != values.length; i++) {
            queue.offer(values[i]);
        }
        return reconPreOrder(queue);
    }

    public static Node reconPreOrder(Queue<String> queue) {
        String value = queue.poll();
        if (value.equals("#")) {
            return null;
        }
        Node head = new Node(Integer.valueOf(value));
        head.left = reconPreOrder(queue);
        head.right = reconPreOrder(queue);
        return head;
    }
}
